Question

A student has two solution of a substance. Solution-1: 25M, 400mL and Solution-2: 30M, 300M. What is the molarity of the final solutions if these two solutions are mixed?

(a) 27.14

(b) 22.14

(c) 14.22

(d) 14.27

This question was addressed to me at a job interview.

This intriguing question comes from Concentration-I in chapter Introductory Concepts of Chemical Process Calculation

Answer 1

The correct answer is (a) 27.14

Best explanation: M = (M1V1 + M2V2 )/(V1 + V2).